Refrigeration



June 18, 1946. w w. G. KOGEL 2,402,414

4 REFRI GERATION I 7 Filed Aug. 25, 1942 2 Sheets-Sheet 1 INVENTOR ,4; ATTO NEY June 18, 1946. w. G. KOGEL 2,402,414

REFRIGERATION Filed Aqg. 25, 1942 2 Sheets-Sheet2 4 A'r roRNEv' ..freely and with certainty.

' Patented June 18, 1946 UNITED STATES PATENT OFFICE- Wilhelm Georg Kiigel, Stockholm, Sweden Application August 25, 1942, Serial No. 455,983

' In Sweden August 27, 19 41 The present invention relatesto absorption refrigerating apparatus of the type in which a heatoperatedpump maintains liquid circulation through the boiler of the apparatus and in which the heat supply to the pump and the boiler takes 'woundround the lower part of the flue located between the lower edge of the jacket and that of the flue. The poor solution is taken out from the boiler through a tube connected to its lowest part, whereas the supply of rich solution to the pump takes place through a conduit connected to the pump coil arranged below'the boiler. The

13 Claims. (CL 62119.5)

radiation owing to the overheating. The boiler being extended downward to a level below the pump, a corresponding shortening of'the part of the boiler located above the pump may be eifected in many cases, since, in spite of such a shorten-' and formed into a rectification column without outer heat supply.

The invention will in the following be more fully described with reference to the embodilower part of the flue is thus always cooled by the solution passing through the pump and the liquid content of the higher located boiler jacket.

It has previously been proposed to build into the boiler insulation besides the boiler and its pump also the liquid heat exchanger of the apparatus in order to reduce, in this manner the losses through radiation. It has, however, proved extremely diiilcult to realize this proposal in actual practice, because the liquid heat exchanger must be arranged in such a manner that the gas bubbles possibly produced therein can be evacuated The simplest solution of this problem has proved to consist in winding the exchanger in a coil e. g. concentric with the flue and located immediately below the pump. Especially in the case of gas and oil operation this arrangement of the exchanger is, however, inconvenient owing to the difllculty of disposing the heat source. According to the present invention all these difliculties are, however, eliminated, this being eflected substantially by extending the boiler downwardly from the liquid pump and arranging the extended part in heat-conducting contact with the likewise downwardly extended flue. This makes it possible to extend the liquid heat exchanger in the manner indicated above and to place the heat-source on a level with the thus pumped. This solution is supplied through lower edge of the exchanger or on a lower level I without any overheating of the downwardly extended flue with its attendant ruiningof the flue ments shown diagrammatically in the accomfeatures of the invention will be seen and in which v Fig. 1 shows diagrammatically an absorption refrigerating apparatus operating with an inert gas; Figs. 2, 3 and 4 show a number of modified embodiments of the boiler according to Fig. 1-; and Fig. 5 is a cross-sectional view of the boiler on line 5-5 in Fig. 2;

In Fig. 1, l0 designates a tube operating as a flue, .to which another tube It is welded'along. a common generatrix. Below, the tube H is closed, whereas, above, it passes into a conduit 28 leading to'the condenser it of the apparatus. The tube It serves as a boiler, and the vapours expelled are led through. the conduit 28 to the condenser. The poor solution flows through a conduit 30, the outer jacket of the liquid heat exchanger l3 and the conduit It to theab'sorbe'r I5 01 the apparatus. The liquid circulation pump of the apparatus is designated by reference numeral l2 and is formed of a narrow tube which.

below, is a continuation of the inner tube of the heat exchanger l3 and, above, runs into the boiler tube ll into which the rich solution is the inner tube of the heat exchanger l3 from the absorber vessel l6 of the apparatus. As already stated, the refrigerating apparatus shown in 1 works with the help of an inert gas, which, in a manner known per se, circulates through the evaporator of the apparatus, not shown, as well as its gas heat exchanger designated by reference numeral 20, a conduit 2|, the absorber vessel [6, the absorber IS, the exchanger 20 and finally the evaporator. The liquid refrigerant is supplied to the evaporator from the condenser [8 through a conduit 19 provided witha U-seal. Finally, pressure vessel 25 of a kind known per se is, in the embodiment shown, connected by means of conduits 21 and 26 to the cirmaterial and high increase of the losses through 56 culation system of the gas. Both thecondenser l8 and absorber it may be air-cooled and, if desired, provided with cooling flns.

Asappears from Fig. 1, the poor solution is carried of! from the boiler tube II from a part of same located substantially higher than the bottom of the boiler, a pocket without a bottom outlet being thus formed. This liquid pocket is, however, like the remainder of the boiler, in heatconducting connection with the flue l and receives from the latter considerable quantities of heat. In the embodiment shown, the heat source is, in fact, assumed to be located at the lower mouth of the flue ID, the wall of which are thus dlrectlyheated. The pump i2 is, along a certain length, welded to the tube Ill, on a level with or somewhat above the level of the outflow of the poor solution from the boiler. The connecting conduits from the exchanger to the boiler or the pump, respectively, will thus be very simple and short, particularly if the liquid heat exchanger is arranged in the shape of a tube coil wound around the boiler, inclusive of the pump and flue, said coil, together with the boiler, being provided with a hood or the like of heat-insulating material, not shown. a

' It is generally desirable to efiect a regulated circulation of the solution also in the part of the boiler located below the pump in order to prevent said solution being too vigorously boiled out, as otherwise its refrigerant concentration would be too low. In Order to bring about such a circulation it is possible as shown diagrammatically in Fig. 2, to insert a partition 3! into the boiler tube Ii, said partition terminating below somewhat above the bottom of the boiler and, above, somewhat above the entry of the pump tube into the boiler tube ll. Fig. 5 shows diagrammatically a-cross section along the line 5-5 of the boiler tube ii in Fig, 2. The partition 3! is suitably welded along the inner surface of the tube by spot welding which may be efiected electrically with two electrodes disposed diametrically on the outside of the tube. The partition is so disposed that the relatively rich solution raised by the pump is supplied to the tube half located nearest to the flue where the boiling of the solutioncontinues, its concentration gradually decreasing. By. the raised liquid. the liquid column in said boiler half is continually pressed downward, passing at the bottom to the boiler half located on the left in the upward direction and beingsupplied to the absorber through the conduit an and the heat exchanger it. In the part of the left half of the boiler'located above the pipe 30. for the poor solution a boilingout also takes place, partly owing to direct heat transfer through the partition 3i and by way of the jacket wall of thetube from the hue, partly generally also through the rising vapour. The solution in the upper part of the left boiler half is, in fact, generally richer than any other solution in the-boiler, this being due tothe fact that the condensate precipitated in the vapour tube 28 and arectifier arranged; if desired, be-

hind said tube flows down along the bottom of a regulated flow-through the pocket of the boiler side the boiler tube Ii a suitably concentrically located tube 32 which, below, terminates somewhat above the bottom or the boiler and into the upper part of which runs the pump tube i2. In a manner wholly analogous to what has been described in connection with Fig. 2 a regulated flow of boilersolution is obtained in this case from the inner tube downwards and along the boiler tube H up to the pipe 30 for the poor'solution.

Fig. 4 shows a further embodiment of the boiler according to the invention. In this boiler the partition has been replaced by an insert 53 comprising a band the width of which corresponds approximately to the inner diameter of the tube and in which tongues 34 have been punched and alternately bent at right angles to both sides of the band. Inserts of this kind previously used in rectiflers possess, as is well known, the quality of facilitating rectification by, on the one hand, preventing the'intermixture of different liquid layers and, on the other hand, by effecting an intimate contact betweenthe vapour and the liquid. The solution will thus flow in the vertical direction only to a very limited extent and for this reason it is not generally suitable to let an insert of this type extend downwards into the pocket of the boiler, as this would make the solution in the pocket extremely poor and considerably increase th temperature and the pressure. In the device according to Fig. 4 there does not, however even if th insert terminates above the tube 30, ensue any regulated flow in the pocket, but it has been proved that the movement of boiler solution is enough for preventing an increase of temperature disturbing the operation.

The invention may be varied in several ways, without departing from the spirit of the invention, and is not thus limited tothe examples shown diagrammatically. Therefore, without limiting myself in this respect, the invention is defined by the appended claims:

I claim: a

1. In an absorption type refrigerating system, an upright heating flue, and a circuit for absorption liquid including a generator vessel having a wall in heat transfer relation with said flue, an absorber, and a heat operated vapor lift conduit separate from and outside of said generator and having a heat receiving and vapor forming part which is in heat transfer relation with said flue and arranged in said circuit to receive liquid from said absorber and deliver liquid to said generator, the heat transfer relation absorber, a heat operated vapor lift conduit septhe vapour tube into the left boiler hali. It is thus evident that the partition not only effects medium being forced to pass through liquid lay ers having a higher concentration.

Instead of a simple partition it is possible, as shown diagrammatically in Fig, 3, to arrange inarate from and outside of said generator and having a heat receiving and vapor forming part which is in heat transfer relation with saidflue and arranaedin said circuit to receive liquid from said absorber and deliver liquid to said generaton-the heat transfer relation between said generator and flue being at least in part at an elevation below that of said Part of said vapor lift conduit, a nd a conduit for conducting to said absorber liquid from said generator, said last conduit communicating with' said generator so that the lowerpart'of said se arator. forms a liquid pocket below the conduit.

3. A system as set forth in claim 2 in which said generator is provided internally with bafiie structure for directing movement of fluid therein..

structure arranged to cause flow of liquid therein downward in one part of the generator and upward in another part of the enerator.

7. A system as set forth in claim 2 in which said generator is a tube secured in thermal contact to said flue and closed at its lower end.

8. A system as set forth in claim 2 in which said circuit for absorption liquid also includes a heat exchanger in the form of a tube coil located around the liquid pocket part of said generator.

9. A system as set forth in claim 2 inwhich said generator is provided internally with baffle structure in the upper part thereof to form a rec- 35 v pocketed body of liquid.

tifying column.

10. A system as set forth in claim 2 in which said generator is a tube closed at its lower end,

6 and.- said generator is provided internally with a tubular partition wall dividing the generator into chambers communicating at their upper and lower ends.

11. A system'as set forth in claim 1 in which said generator is provided internally with a partition dividing the generator into chambers com-' municating at their upper and lower ends.

12. An absorption type refrigeration system employing inert gas and having a generator with an outlet a substantial distance above the bottom thereof, said outlet forming a pocket in the generator therebelow holding a body of liquid out of circulation in the system, and a heating flue arranged in heat conductive relation with one side of the generator vessel to cause local circulation of the pocketed body of liquid; I

13. An absorption type refrigeration system employing inert gas and having a vessel with an outlet a substantial distance above the bottom thereof, said outlet forming a pocket in the V- sel therebelow holding a body of liquid out of circulation in the system, and a heating conduit arranged in heat conductive relation with onev side of the vessel to cause local circulation of the GEORG OG L. 

